Cleaning Up Large Mercury Spills

If one pound or more (more than one fluid ounce or two tablespoons) has been
spilled and gets into the environment, i.e., outdoors, sewer, groundwater or
surface water, or that threatens public health, it must be reported immediately.

Before cleaning any mercury spills, be sure to read and follow
the precautions
found in the general mercury spill fact sheet.

Evacuate the Spill Area

Before people leave the spill site, be sure they had not come in contact with
or stepped in the mercury. When directing people out of the area, be sure to
avoid traffic going through the spill site. Those who may have come into contact
with mercury should be directed to the nearest safe location and asked to stay
there until contamination can be assessed and clean up completed. Once
immediately outside of the spill area, contaminated (direct contact with
mercury) shoes and clothes should be removed, double-bagged and sealed. Not
doing so can result in mercury being tracked around the building or home, making
the situation worse.

Seek Professional Assistance for Clean-Up

Call either the local fire department or a contractor.
Spills of this size require specialized equipment and demanding control
measures. It is also likely larger spills will release dangerous levels of
vapors into air and specialized protective equipment, such as self contained
breathing apparatus, will be necessary for responders.

Test Clothing/Personal Belongings

Clothing and personal belongings that were contaminated or suspected of being
contaminated can be placed in a plastic bag, which should then be sealed and
allowed to sit for about an hour. Test the headspace of the air in the bag with
a mercury vapor analyzer capable of reliably detecting concentrations less than
0.1 ug/m3. If the level in the headspace in the bag is less than 10 ug/m3, the
clothes and belongings can be returned to the owners. Other procedural guidance
for decontamination can be found at the Ohio EPA website:
http://www.epa.state.oh.us/opp/mercury_pbt/mercury.pdf. It should be noted that the cost to clean and monitor
clothes and belongings could exceed the value of those items. Clean up cost
should be weighed against item value to prevent unnecessary expense.

Continue Ventilation

Ventilate as much as possible to completely air out the room or spill zone
with outside air.

Monitor

Air in the spill area should be tested using
NIOSH Method 6009
or similar method with comparable limit
of detection. Levels should be below 1 ug/m3 for residential environments and 3
ug/m3 for commercial environments.

Inventory All Remaining Mercury-Containing Devices and Replace Them With
Mercury Free Alternatives

The best way to address a mercury spill is to prevent it from ever happening
in the first place. For assistance with reducing mercury contact your local
health unit or the North Dakota Department of Health.

Medical Testing

If significant exposure is believed to have occurred, you should discuss with
your family doctor whether urine mercury testsshould be conducted for
the people who use the area the most. Results should not be above 20 micrograms
per liter of urine (20ug/L).